JPH0362047A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent trouble from being generated by providing a judging means which judges whether or not outputted voltage from an outputting means is within an acting voltage range specified by a specifying means. CONSTITUTION:The constitution of the device is made so that a fixing device with a different acting voltage range is freely attachable/detachable, and for those carrying out image formation, power source voltage is outputted from an outputting means 68, the acting voltage range of the fixing device 33 is specified by a specifying means 70, and whether or not the outputted voltage from the outputting means 68 is within the acting voltage range specified by the specifying means 70 or not is judged by the judging means 133. Thus, when an error is generated in the setting of the acting range against AC inputting voltage, trouble can be prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention is applicable to, for example, laser printers, digital copying machines,
The present invention relates to an image forming apparatus used in facsimile machines and the like.

(Prior Art) Conventionally, in an image forming apparatus such as a laser printer, a photoreceptor, a developing device, a fixing device, etc. are made into separate units and can be inserted (installed) or removed in a cartridge-type manner. (being developed.

In such devices, fixing devices having different alternating current (AC) input terminals can be arbitrarily set, and devices in which the operating ranges of these devices can be changed by switches have been put into practical use. For example, if the AC input voltage is 10
0V, 50H2/60H2, North America 115■, 60H2,
Yoguchi Sonoku 220v, 50H2 is used, domestic 1
00 Vl: An operating range of 80v to 120v is set for North America 115vl: An operating range of 96v to 144v is set for Europe, 176v for Europe 220v.
The operating range is set from v to 288V.

However, if the user makes a mistake in the settings, the following two problems may occur.
There are two problems.

The first problem is that if the input terminal is smaller than the operating range (input voltage - operating range), the temperature of the fixing device does not rise and a fixing failure occurs, or switching occurs. ! ! There is a problem that the power source may malfunction.

The second problem is that when the input terminal is larger than the operating range (input voltage>operating range), the fixing device, fan, power supply, etc. may malfunction or melt.

The only protection against the second problem is a fuse inserted in series with the AC input line. In the case of this fuse, there are variations in characteristics, it takes time for the fuse to blow, and a fixing device or the like connected after the fuse often breaks down.

In addition, in the case of the first problem, the fuse does not blow out and does not work as a protective device, so especially if you are using a switching type power supply, it may be difficult to output a constant output even though the AC input voltage is low. This places a heavy burden on the switching transistors, often causing them to malfunction.

Therefore, the above-mentioned device has the drawback that failure occurs if an error occurs in setting the operating range for the AC input voltage.

(Problem to be Solved by the Invention) This invention eliminates the drawback that failure occurs when an error occurs in the setting of the operating range for AC input voltage. An object of the present invention is to provide an image forming apparatus that can prevent failures even when errors occur.

[Structure of the Invention] (Means for Solving the Problems) The image forming apparatus of the present invention has a structure in which fixing devices with different operating voltage ranges are detachable, and an output that outputs a power supply voltage is used to form an image. an instructing means for instructing an operating voltage range of the fixing device; and a determining means for determining whether the output voltage from the output means is within the operating voltage range instructed by the instructing means. .

An image forming apparatus of the present invention has a structure in which fixing devices having different operating voltage ranges are detachable and forms an image, including an output means for outputting a power supply voltage, and an instruction means for indicating the operating voltage range of the fixing device. , a determining means for determining whether the output voltage from the output means is within the operating voltage range instructed by the indicating means, and when the output voltage is within the operating voltage range as a result of the determination by the determining means; The image forming apparatus further includes supply means for supplying the output voltage from the output means to the fixing device.

An image forming apparatus of the present invention has a structure in which fixing devices having different operating voltage ranges are detachable and forms an image, including an output means for outputting a power supply voltage, and an instruction means for indicating the operating voltage range of the fixing device. , a determining means for determining whether or not the output voltage from the output means is within the operating voltage range instructed by the indicating means; as a result of the determination by the determining means, if the output voltage is within the operating voltage range; , supply means for supplying the output voltage from the output means to the fixing device, and the determination means that if the output voltage is outside the operating voltage range, the output voltage is outside the operating voltage range; It consists of a display means for displaying.

The image forming apparatus of the present invention has a fixing device having an operating voltage range that is removable and forms an image, including an output means for outputting a power supply voltage, and an instruction means for indicating the operating voltage range of the fixing device. , a determining means for determining whether or not the output voltage from the output means is within the operating voltage range instructed by the indicating means; as a result of the determination by the determining means, if the output voltage is within the operating voltage range; , supply means for supplying the output voltage from the output means to the constant voltage device, and when the output voltage is smaller than the operating voltage range as a result of the judgment by the judgment means, display a message to that effect, or It is comprised of a display means that displays a message to that effect when the voltage is higher than the operating voltage range.

(Function) The present invention has a structure in which fixing devices with different operating voltage ranges are detachable and forms an image, in which a power supply voltage is outputted by an output means, and the operating voltage range of the fixing device is indicated by an indicating means. However, it is determined whether the output voltage from the output means is within the operating voltage range instructed by the instruction means.

This invention has a structure in which fixing devices having different operating voltage ranges are detachable and forms an image, in which a power supply voltage is outputted by an output means, the operating voltage range of the fixing device is indicated by an indicating means, and the above-mentioned It is determined whether the output voltage from the output means is within the operating voltage range instructed by the instruction means, and as a result of this judgment, if the output voltage is within the operating voltage range, the output from the output means is A voltage is supplied to the fixing device.

The present invention has a structure in which fixing devices with different operating voltage ranges are detachable and performs image formation. outputting a voltage with an output means, instructing an operating voltage range of the fixing device with an indicating means, and determining whether the output voltage from the output means is within the operating voltage range instructed by the indicating means; If the output voltage is within the operating voltage range as a result of this determination, the output voltage from the output means is supplied to the fixing device, and if the output voltage is outside the operating voltage range as a result of the determination by the determination means. In addition, a display is provided to indicate that the output voltage is outside the operating voltage range.

This invention has a structure in which fixing devices having different operating voltage ranges are detachable and forms an image, in which a power supply voltage is outputted by an output means, the operating voltage range of the fixing device is indicated by an indicating means, and the above-mentioned It is determined whether the output voltage from the output means is within the operating voltage range instructed by the instruction means, and as a result of this judgment, if the output voltage is within the operating voltage range, the output from the output means is supplying a voltage to the fixing device, and if the output voltage is smaller than an operating voltage range as a result of determination by the determination means, displaying that fact;
Alternatively, when the output voltage is higher than the operating voltage range, a message to that effect is displayed.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the external appearance of an electrophotographic image forming apparatus using a semiconductor laser, and FIG. 3 shows its internal configuration. This image forming device (laser printer) is connected to a host system (external device such as a computer or word processor).
(not shown) via a transmission controller such as an interface circuit. When a print start signal is received from the host system, the image recording operation is started, and the image is recorded on paper as a transfer material and output.

This image forming apparatus has the following configuration.

That is, numeral 1 in the figure is a main body of the apparatus, and a main control board 2 is disposed in the center of the main body 1, as shown in FIG. An electrophotographic process unit 3 for forming images is arranged behind the main control board 2 (to the right in the state shown in Fig. 3), and a plurality of function-adding controls are arranged at the lower front. A control board accommodating section 5 for accommodating a plurality of boards 4 is also provided with a paper discharge section 6 formed at the upper front thereof.

Up to three function addition control boards 4 can be installed depending on the degree of function addition (for example, adding types of fonts, kanji, etc.). Further functions can be added by attaching function-adding IC cards 17 to three IC card connectors 16 arranged on the front edge of the board 4. Furthermore, two interface connectors (not shown) are arranged on the left end surface of the control board 4 for adding functions located at the bottom, and these interface connectors are installed on the left side surface of the device main body 1. It faces the formed opening 18 (see FIG. 2).

Further, a lower portion inside the apparatus main body 1 is a cassette accommodating section 8 that accommodates a paper feed cassette 7.

As shown in FIG. 2, the paper ejection section 6 is a recess formed on the front upper surface of the main body 1 of the apparatus, and the front edge of the paper ejection section 6 has a recess that can be folded into the paper ejection section 6 or unfolded as shown in the figure. A rotatable paper discharge tray 9 is provided. Further, a notch 9a is formed in the center of the front end of the paper ejection tray 9, and a rotatable U-shaped auxiliary member that can be accommodated in the notch 9a or unfolded as shown in FIG. A paper discharge tray 10 is provided. The size of the paper discharge section 6 can be adjusted according to the size of the paper P to be discharged.

Further, on the upper surface of the left frame portion 1a of the main body of the apparatus located on the left side of the paper ejecting portion 6, a control panel 14 is provided with an LED II for display, a 7-segment display 12 for displaying a two-digit status, and a switch 13. are arranged, and a manual feed tray 15 is attached to the rear side of the apparatus main body 1.

Next, the electrophotographic process unit 3 that performs electrophotographic processes such as charging, exposure, development, transfer, peeling, cleaning, and fixing will be described with reference to FIGS. 3 and 4.

A drum-shaped photoreceptor 20 serving as an image carrier is disposed approximately in the center of the unit accommodating portion, and this photoreceptor 2
Around the 0, along the direction of rotation, there is a spare charger 21 made of a scorotron, and a magnetic brush that simultaneously performs the development process and the cleaning process of the exposure part 22a1 of the laser exposure unit 22 as an electrostatic latent image forming means. type developing device 23, transfer charger 24 consisting of a scorotron
, a memory removal brush 25, and a pre-exposure lamp 26 are arranged in this order.

Further, inside the apparatus main body 1, paper P fed from the paper cassette 7 via the paper feeding means 27 and paper P manually fed from the manual feed tray 15 are transferred between the photoreceptor 20 and the transfer charger 24. A paper conveyance path 29 is formed which leads to a paper discharge section 6 provided on the upper surface side of the apparatus main body 1 via an image transfer section 28 between the two.

A pair of transport rollers 30. Aligning roller pair 31. and a conveying roller pair 32 are arranged, and a fixing device 33 as a fixing unit and a paper ejection roller unit 34 are arranged on the downstream side. Further, a cooling fan unit 35 is disposed above the location where the pair of conveyance rollers 32 are disposed.

Note that an aligning switch 36 is provided near the aligning roller pair 31, and an aligning switch 36 is provided near the aligning roller pair 31.
A conveyance guide 37 is provided near 8.

When a print start signal is received from the host system, the drum-shaped photoreceptor 20 rotates and the photoreceptor 20 rotates.
is charged by the charger 21. Next, the laser beam a modulated in response to the dot image data from the host system is scanned and exposed onto the photoconductor 20 using the laser exposure unit 22, and an electrostatic latent image corresponding to the image signal is formed on the photoconductor 20. form. This electrostatic latent image on the photoreceptor 20 is formed by toner t in the developer magnetic brush D' of the developing device 23.
The image is developed and visualized.

Meanwhile, in synchronization with this toner image forming operation, paper P taken out from the paper feed cassette 7 or manually fed from the manual feed tray 15 is fed through a pair of aligning rollers 31, and is formed on the photoreceptor 20 in advance. The toner image thus obtained is transferred onto the paper P by the action of the transfer charger 24.

Next, the paper P passes through two paper conveyance paths and reaches the fixing device 3.
The toner image is fused and fixed onto the paper P by feeding the toner image 3I.

Thereafter, the paper is discharged to the paper discharge section 6 via the paper discharge roller uni-soto 34.

Note that after the toner image is transferred onto the paper P, the residual toner remaining on the photoreceptor 20 is removed by a memory removal brush 25 made of a conductive brush, thereby performing memory removal.

Further, as shown in FIG. 4, the fixing device 33 includes a heat roller 41 having a built-in heater lamp 40, and a pressure roller 42 that is in pressure contact with the heat roller 41. The toner image is fused and fixed on the paper P as the paper P passes between them.

Further, the heat roller 41 and the pressure roller 42 are surrounded by a lower casing 43 and an upper casing 44, and are structured to prevent heat from escaping to the outside as much as possible to ensure a favorable temperature atmosphere necessary for fixing. ing.

A cleaner 45 is in contact with the heat roller 41, and the temperature is controlled by a thermistor 46 to maintain the temperature necessary for fixing. It is configured to be done.

Further, a paper guide 48 is disposed within the upper casing 44 and near the upstream side of the contact portion 47 between the heat roller 41 and the pressure roller 42, and the paper guide 48 is arranged to ensure that the leading edge of the paper P guided to the fixing device 33 is guided to the heat roller. 41 and the pressure roller 42. Note that on the paper exit side of the fixing device 33, a paper guide 49 is provided integrally with the lower casing 43 to guide the fixed paper P to the paper discharge roller unit 34.

Further, the transport guide 3 is located on the transport direction side of the transfer charger 24 and guides the non-image side of the paper P.
7 is in a grounded state and functions to electrostatically attract and float the paper P.

Further, the paper ejection roller unit 34 includes a lower roller 50
and an upper roller 51, and the paper P is
A static eliminating brush 52 is provided in contact with the non-image forming surface of the image forming apparatus. Upper roller 51 and static elimination brush 5
The upper half including the transport guide 37. The transfer charger 24 and the like are attached to the lower surface side of the top cover 60 of the main body 1 of the apparatus.

The top cover 60 can be rotated up to a maximum of about 120° as shown in FIG. This allows most of the paper transport path 29 to be exposed, and also allows the equipment facing the paper transport path 29 to be exposed.

This makes it easy to remove paper jams and perform maintenance, inspection, and replacement of equipment. Note that 62 shown in FIG. 5 is an ozone filter, and 63 is a toner cartridge.

Further, the rear cover 64 of the apparatus main body 1 shown in FIG. The curved conveying section can be opened, and the paper P stuck in this section can be easily removed.

Furthermore, as shown in FIG. 5, the fixing device 33 can be attached and detached with the top cover 60 open. At the bottom of the fixing device 33, as shown in FIG. 13 and FIG.
It is designed to be electrically connected to. The connecting portion 172 includes guide pins 170 and 170 for insertion,
and the width is longer and the height is higher than that of the connecting portion 172;
Protective sheet metal 17 to prevent the connecting part 172 from being damaged
1 is provided. The connecting portion 172 includes a connector terminal 172a.

172b. The connector terminal 172a is a terminal to which the terminal block 40 inside the fixing device 33 and a thermo fuse (not shown) are connected, and since a current of 10 A flows when the AC input terminal is 100 V, it becomes a large terminal. There is. The connector terminal 172b is connected to a thermistor 46 inside the fixing device 33 and a fuse 1 to be described later.
74, 175, and 176 are connected terminals, and since the flowing current value is about 1 to 300 mA, the area of the terminals is smaller than that of the connector terminal 172a.

Further, as shown in FIG. 4, the laser exposure unit 2
2 is a semiconductor laser oscillator 90 (not shown in detail), a polygon scanner 93 consisting of a polygon mirror 91 and a mirror motor 92, a second lens 95 for FE, a second lens 95 for FE, and a predetermined scanned laser beam a. It is composed of reflecting mirrors 96, 97, etc. for scanning to the position.

Further, the control board 101 of this laser exposure unit 22 is connected to the main control plate 2 via a connector 102.

Furthermore, the laser exposure unit 22 is housed in a synthetic resin casing 103 that is open at the bottom, and the bottom opening of the casing 103 is connected to a metal shield plate 104.
At the same time, the casing 1
A shield cover 105 made of metal and also serving as a reinforcing plate is superimposed on the upper surface side of 03. A conductive contact piece 106 is connected to the shield cover 105.
When the laser exposure unit 22 is attached to a predetermined position via an attachment means (not shown), this contact piece 106 comes into contact with a metal guide rail that slidably guides the developing device 23, and the contact piece 106 comes into contact with a metal guide rail that slidably guides the developing device 23. This prevents malfunctions caused by the negative effects of static electricity on the inside.

Note that the photoreceptor 20 uses an organic photoconductor,
It has a structure in which a charge generation layer and a charge transport layer covering this charge generation layer are formed on the surface of an aluminum cylinder.

Further, in order to simplify the electrophotographic process, the developing device 23 employs a reversal developing method and a method in which the residual toner t after transfer is removed at the same time as the developing. As shown in FIG. 4, this developing device 23 includes a photoreceptor 20 and a developing roller 122 provided in a casing 121 having a developer accommodating portion 120. contains a two-component developer consisting of toner (colored powder) T and carrier (magnetic powder) C. Further, a sliding contact portion with the photoreceptor 20 of the developer magnetic brush D′ formed on the surface of the developing roller 122;
That is, a doctor 124 for regulating the thickness of the developer magnetic brush D' is provided upstream of the development position 123 in the rotational direction of the photoreceptor 20. Further, the developer storage section 120 includes a first. Second developer stirring body 125
゜126 is accommodated. Note that the developing device 23 includes:
Toner cartridge 63 (fifth) as a toner supply device
(see figure) is installed to replenish the developer storage section 120 with toner t as appropriate.

Further, the developing roller 122 has three magnetic pole parts 127.12.
It consists of a magnetic roll 130 having a diameter of 8.129 mm, and four non-magnetic sleeves 131 which are attached to the magnetic roll 130 and rotate clockwise in the figure. magnetic roll 130
Of the three magnetic pole parts 127, 128, 129, the magnetic pole part 12g facing the development position 123 is the north pole, and the other magnetic pole parts 127, 128 are the south pole.

Also, the angle e between the magnetic pole part 127 and the magnetic pole part 128 (
(see Figure 4) is 150'', magnetic pole part 128 and magnetic pole part 129
The angle e (see FIG. 4) is set to 120°. The electrostatic charge on the photoreceptor 20 is caused by the potential difference between the mechanical scraping force caused by the magnetic brush development using the two-component developer, the charging potential caused by the reversal development, and the development bias applied to the magnetic brush D'. Mechanical development at the same time as latent image development, 1! The residual toner t is collected by air.

Furthermore, as shown in FIG. 5, this developing device 23 includes:
Photoreceptor 20. Electrostatic charger 21. Memory removal brush 2
5 and the like are integrated into a process cartridge 85, and this process cartridge 85 can be taken in and out of the apparatus main body 1. Further, a cleaning brush 144 for cleaning the lower roller 31a of the aligning roller pair 31 is attached to the upper surface of the process cartridge 85.

Further, on the back side 1a of the main body 1, as shown in FIGS. 6 and 8, there is a power switch 68 for opening and closing the AC power supply.
A connector part (female pin) 69 to which a connector part (male pin) 57 of the AC power cord 66 shown in FIG. 7 can be attached and detached, an input terminal changeover switch 70, a green indicator 71, and a red indicator 72 are provided. Green indicator 71, red indicator 7
2 is controlled to turn on by an overvoltage protection device 161, which will be described later. The connector part 69 has a female pin configuration that prevents the active part from being exposed even if the connection with the connector part 57 is disconnected when the plug of the AC power cord 66 is plugged into a power outlet. The green indicator 71 lights up when the AC input voltage reaches the operating voltage range of the device, and the red indicator 72 lights up when an overvoltage AC input voltage exceeding the operating voltage range of the device is input. Each display 71 tells the user whether the input voltage is appropriate or not.
．． This can be notified by whether or not 72 is lit.

The input voltage changeover switch 70 is a switch for indicating the operating voltage range for the input voltage by switching in accordance with the operating voltage of the image forming apparatus, and is 100V in Japan and 115V in North America.

It can be switched to the European 220v operating voltage.

The operating voltage range for each input voltage is set in the range of 80% to 120% of the input voltage, and before and after that, the indicator lights up, or the bidirectional thyristor 182 for overvoltage protection, which will be described later, turns on. It will be turned off. However, in the case of 220V in Europe, considering the common specifications between the UK and the continent, 80% of 220V, 240V (7
) 120% is set as the operating voltage range.

For example, as shown in FIG. 11, when the input voltage selector switch 70 is set to the 100V position, if the AC input voltage becomes lower than 80V, the green indicator 7
1. Turn off the red indicator 72 and turn off the bidirectional thyristor 182.
is turned off, and when the AC input terminal is between 80V and 120V, the green indicator 71 lights up and the bidirectional thyristor 182
is turned on, and when the AC input terminal becomes higher than 120V, the green display 71 and the red display 72 are turned on, and the bidirectional thyristor 182 is turned off.

In addition, when the input terminal selector switch 70 is set to the 120V position, if the AC input voltage becomes lower than 96V, the green indicator 71 and red indicator 72 are turned off, and the bidirectional thyristor 182 is turned off. , AC input voltage is 9
When the voltage is between 6V and 144■, the green indicator 71 is lit, the bidirectional sirisk 182 is turned on, and the AC input voltage is 1
When the voltage exceeds 44V, the green indicator 71 and red indicator 72 are turned on, and the bidirectional thyristor 182 is turned off.

In addition, when the input voltage selector switch 70 is set to the position 220■, when the AC input voltage becomes smaller than 176V, the green indicator 71 and the red indicator 72 are turned off, and the bidirectional thyristor 182 is turned off. off and the AC input voltage is between 176V and 288V, the green indicator 71
lights up, turns on the bidirectional thyristor 182, and when the AC input voltage becomes greater than 288v, the green indicator 7
1. Turn on the red indicator 72 and turn on the bidirectional thyristor 182.
Turn off.

Next, the control system of the present image forming apparatus will be explained with reference to the block diagram shown in FIG. In the figure, 131 is an external device that is connected via the aforementioned interface connector.

As this external device 131, a host system such as an electronic computer, a word processor, an image processing device, etc. is connected. This external device 131 is an interface circuit 132
It is electrically connected to this device via.

The following interface signals for this interface circuit 132 are prepared.

In other words, the IVCLKO signal is transmitted from this device to the external device 132.
The external device 131 outputs 8-bit image data IVD in synchronization with this clock signal.
Output AT70-00.

The IH8YNO signal is a horizontal synchronization signal that is output from the present device to the external device 131 prior to the transfer of image data for one scan. The I DAT71 to 01 signals are bidirectional 8-bit data bus signals, which receive commands from the external device 131 via this bus, and output status indicating the status of this device to the external device 131. .

The ID5TAO signal is a signal that determines the direction of data transfer on the 8-bit data bus, and the 15TBO signal is a strobe signal for this device to receive commands, both of which are output from the external device 131.

The IBSYO signal is a busy signal indicating that the device is processing a command from the external device 131. IA
The TN1 signal is an attention signal output by the device when a situation that the external device 131 should immediately know about occurs in the device. The IPRDYO signal is a signal indicating that the device is in a ready state. The IPRIMEO signal is a reset signal that the external device 131 outputs to this device. I 5
The CLRI signal is a clear signal that the device outputs to the external device 131 when the device is powered on and off.

Signals taken into the device from this interface circuit 132 are supplied to a control circuit 133 and an image signal processing circuit 137.

The control circuit 133 is composed of a microcomputer and its peripheral circuits, and processes various data and performs various controls.

The main functions of this control circuit 133 are listed as follows:
It is as follows. (1) Interface circuit 13
2, that is, commands from the external device 131, and controls each part of the device according to the instructions. Also,
The status corresponding to the command is output to the external device 131 through the interface circuit 132. Also I
Controls the output of the ATN1 signal, lPRDYO signal, and l5CLR1 signal. (2) Control panel 14
The display contents are output to a display circuit 134 that drives the LED II and 7-segment display 12.

(3) On/off control of various solenoids 135 is performed. <4> Information from various switches 136 is taken in and processed.

(5) Setting various parameters and sending internally generated pattern data to the image signal processing circuit 137. (
6) For the mirror motor/laser drive circuit 138, on/off control of the mirror motor 92, laser emission power setting, and power monitoring are performed. (7) Controls on/off of the light emitting diodes of the toner concentration sensors 143 and 144, and processes toner concentration information from both sensors 143 and 144. (8) Control the high voltage power supply 145. That is, output on/off control and output power setting for the charging charger 21, output on/off control and output power setting for the charging grid 140, output on/off control and output power setting for the transfer charger 24, and transfer grid 139. On/off control and output power setting of the output for the developing bias, on/off control of the output and output power setting for the memory removal brush 25 are performed. It also monitors whether each output is operating normally.

(9> On/off control of the main motor 150 and monitoring of steady rotation are performed.

(lO> On/off control of the fan motor 151 is performed. (11) On/off control of the pre-exposure lamp 26 is performed. (12) Heat roller 4 of the fixing device 33
solid state relay (SSR) 16 by monitoring the temperature of
5 to control the heater lamp 40 on and off.

(13) Depending on the state of the two fuses in the fixing device 33 and the count contents of the memory 153, old and new discrimination, life management, life discrimination, voltage specification of 100V series and 200V series, etc. are performed. (14) The switching signal from the input voltage selection switch 70 causes the device to switch between 100V, 120V, and 220V.
It is determined whether or not the voltage specification determined by the fuse in the fixing device 33 matches the setting of which voltage specification the fixing device 33 has.

As briefly explained above, the control circuit 133 corresponds to the command section of this device.

As shown in FIG. 9, the heater lamp 40 of the fixing device 33 includes the AC power cord 66, the connecting portion 57,
breaker 160, power switch 68, overvoltage protection device 161, 1; 7J conversion switch 164, solid state relay (SSR) 165, and thermofuse 1
An AC input terminal from an AC source (not shown) is supplied via 66. Further, the high voltage power supply 145 connected to the subsequent stage of the overvoltage protection circuit 161 also has an A
AC input voltage from C power supply is supplied, and selector switch 1
The fan motor 151 connected to the rear stage of 64 also has A.
Pressure is supplied to the AC input cuff from the C power supply.

The overvoltage protection device 161 is provided after the power switch 68, and is provided when the supplied AC input voltage is lower than the operating voltage range (low voltage) or when the supplied AC input terminal is at a voltage higher than the operating voltage range. (overvoltage), the application of the AC input voltage to the subsequent stage is stopped, and the above-mentioned blue display 71 and red display 72 are controlled to light up. It is constituted by an internal circuit 163 of a bidirectional thyristor 182. The overvoltage protection circuit 162
As shown in the figure, a diode stack 18 for full wave rectification
0, a protective resistor R1 for voltage drop, a changeover switch 181 that switches in conjunction with the input voltage changeover switch 70, and a Zener diode D for voltage drop to the changeover switch 181.
1, D2, D3, a smoothing circuit 183 composed of a Zener diode D4 for Zener clamping, a capacitor cfSC2, and a resistor R2, and resistors R3, R4, and R for voltage division.
5. Consists of an npn transistor T1, resistors R7 and R8, a green indicator 71, a red indicator 72, and a light emitting diode D5. As shown in FIG. 10, the internal circuit 163 includes a photothyristor D6, which constitutes a photocoupler with the light emitting diode D5, a resistor RIO1, an npn type transistor T2, and voltage dividing resistors R11, R12, R13, R.
14, protective resistor R15, diodes D7, D8, D9,
DIO, capacitors C3, C4, C5, resistors R15, R
16 and R17.

The power switch 68 is turned on, and the input voltage selection switch 7
When an AC input voltage within the operating voltage range corresponding to the switching position of 0 is input, the AC input voltage is full-wave rectified by the diode stack 180, and after voltage drop by the protection resistor R1,
It reaches the Zener diodes D1 to D3. At this time, the selector switch 181 is switched according to the switching position of the input voltage selector switch 70. After the voltage of the AC input terminal also drops through the Zener diodes D1 to D4, it is smoothed by the capacitor C1, resistor R2, and capacitor C2, and then is smoothed by the resistor R.
3. Join R4 and R5. The waveforms during this period are as shown in FIG. The waveform after wave rectification is shown, and (c) of the same figure shows the waveform after Zener clamping from the cathode of Zener diode D4,
The figure (d) shows the waveform after capacitor smoothing applied from the capacitor C2 to the resistor R3, the red indicator 72, and the resistor R8.

The voltage divided by resistors R3 and R4 is applied to resistor R5 and transistor T1, but since it is lower than the threshold level of transistor T1, transistor T1 is off and red indicator 72 does not light up. The voltage applied to the light emitting diode D5 through the resistor R8 causes the light emitting diode D5 to
lights up, and the light is transmitted to photothyristor D6. Further, voltage is applied to the green display 71 via the resistor R7, causing the green display 71 to light up. The lighting of the green indicator 71 notifies the user that the AC input terminal is appropriate. The light emitting diode D5 and the photothyristor D6 form a photocoupler.

Furthermore, in the internal circuit 163, the resistor R17 and the capacitor C5 are connected in parallel to the bidirectional thyristor 182, and the bidirectional thyristor 18 is connected in series to the input AC line.
2. It performs noise absorption. Also, capacitor C
3, C4, and resistor R16 absorb noise from the gate G of the bidirectional thyristor 182. When an AC input voltage is supplied where the voltage on the anode A side of the bidirectional thyristor 182 is larger than the voltage on the cathode side, voltage is applied to the diode D7 via the protection resistor R15, the diode D7 is turned on, and the diode D8 is turned on. is off, voltage dividing resistors R12, R
11, joins R13. Since the AC input terminal is a sine wave, the initial divided voltage is below the threshold level of transistor T2, and transistor T2 is off. At this time, when the light emitting diode D5 is lit and the light is transmitted to the photothyristor D6, the photothyristor D6 is turned on and the AC input voltage is changed to the diode DI.
It is applied to the gate G of the bidirectional thyristor 182 through O, turning on the bidirectional thyristor 182. When the AC input terminal rises according to the sine curve, the transistor T
The divided voltage applied to T2 becomes above the threshold level, turning on transistor T2. Transistor T2
The on and off cycles are repeated according to the sine curve of the AC input voltage, and even if light is applied to the photothyristor D6, the photothyristor D6 will not turn on unless the transistor T2 is off, that is, when the AC input voltage is at zero cross. does not turn on, and as a result, bidirectional si risk 1
82 will turn on at the zero cross timing.

In addition, when an AC input voltage is supplied where the voltage on the anode A side of the bidirectional thyristor 182 is smaller than the voltage on the cathode side, the cathode of the bidirectional thyristor 182
A voltage is applied to the gate G1 diode D, and as in the case described above, the bidirectional thyristor 182 is turned on only when the AC input terminal is at zero cross and light is being transmitted to the photothyristor D6.

As described above, when the AC input voltage is within the operating voltage range, the bidirectional thyristor 182 is turned on at the zero cross timing, and the heater lamp 40, high voltage power supply 145, and fan motor 1
Supply voltage to 51 etc.

In this manner, by turning on the bidirectional thyristor 182 at the timing of zero cross, it is possible to prevent surge current from flowing due to the capacitor load in the high voltage power supply 145 and the lamp load of the heater lamp 40.

In addition, when the AC input voltage is a low voltage lower than the operating voltage range, the Zener diodes D1, D2, and D3 will not turn on, the light emitting diode D5 will not light up, and the photothyristor D6 will not turn on.
is off, so the bidirectional thyristor 182 is off. Therefore, when the AC input voltage is low, the heater lamp 40. Since no voltage is applied to the high voltage electric circuit 11iX 145, fan motor 151, etc., failure of the switching power supply due to low voltage operation can be prevented.

In addition, when the AC input terminal has an overvoltage higher than the operating voltage range, the light emitting diode D5
lights up, and the blue display 71 lights up. However, resistance R3
, R4 becomes above the threshold level of transistor T1,
is turned on and the red indicator 72 is lit, but the light emitting diode D5 is turned off and the bidirectional thyristor 182 is turned off. Therefore, when the AC input voltage is an overvoltage, no voltage is applied to the heater lamp 40, high-voltage power supply 145, fan motor 151, etc., so thermal destruction of the heater lamp 40 due to overvoltage can be prevented. At this time, both the green indicator 71 and the red indicator 72 light up,
It is possible to display and notify the user that overvoltage is being applied manually.

Furthermore, since the light emitting diode D5 and the photothyristor D6 are optically coupled, if an optical fiber is used to connect them, the overvoltage protection circuit 162 and the internal circuit 16
It can be placed separately from 3. Furthermore, since the internal circuit 163 switches a large current, it is necessary to lower the wiring impedance.
li need not be subject to such restrictions.

Furthermore, as shown in FIG.
Fuse 174 for life management of 00 series, Fuse 175 for life management of 200 series, Fuse 176 for distinguishing old from new.
are connected at the time of manufacture. In other words, the new 100V specification and 120V specification fixing device 33 has
Fuses 174 and 176 are connected, and fuses 175 and 176 are connected to the new 220V specification fixing device 33. These fuses 174, . . . are connected to the fuse determination circuit 1 via the above-described connector terminal 172b.
It is connected to 73. This fuse determination circuit 173 is connected to the control circuit 133, and under the control of the control circuit 133, the corresponding fuses 174, . . .
・Check the status of 1. It also blows out the fuses 174, . . . .

The fuse judgment circuit 173
5.16, buffer 192.193.194, npn
Type transistor T a % T b % T c s Resistors R20, R21, R22, R23, and diode D
11, D12, D13, D14, D15, and D16. For example, when the control circuit 133 turns on the transistor Tb and a low level signal is supplied from the buffer 194, the control circuit 133 switches the fuse 17
6 is connected and a high level signal is supplied from the buffer 194, the fuse 17
It is determined that 6 is disconnected. When the transistor Tc is turned on, the control circuit 133 determines that the fuse 174 is connected if a low level signal is supplied from the buffer 192, and a low level signal is supplied from the buffer 192. In this case, it is determined that the fuse 174 is disconnected, and when a low level signal is supplied from the buffer 193, it is determined that the fuse 175 is connected, and the high 1 novel signal is output from the buffer 193. is supplied, it is determined that the fuse 175 is disconnected.

The control circuit 133 also includes transistors Ta,
By turning on Tb, a current due to the +24V power supply voltage flows through resistor R20, transistor Ta, and diode D.
12, fuse 175, and transistor Tb. As a result, the fuse 176 is blown.

The control circuit 133 also includes a transistor Ta5.
By turning on Tc, +24V? A current flowing from the li source voltage flows through resistor R20, transistor Ta, diode D13, fuse 175, and transistor Tc. As a result, the fuse 175 is blown. The control circuit 133 also includes a transistor Ta.
, Tc, the current due to the +24V power supply voltage flows through the resistor R20, the transistor Ta, and the diode D.
12, fuse 174, and transistor Tc. As a result, the fuse 174 is blown.

Further, as shown in FIG. 16, when the connection between the fuse 176 and the fuse 174 is determined, the control circuit 133 determines the setting of the new 100 series fixing device 33, and determines that only the fuse 174 is connected. 100
Determine the setting of the fuser 33 of the old model of the system and set the fuse 17.
6 and fuse 175, the setting of the new fixing device 33 of the 200 series is determined, and the fuse 175 is connected.
If it is determined that only one fuse is connected, the settings of the old 200 series fixing device 33 are determined, and which fuse 174,...
・If the connection of fuse 1 is also not determined, or
If it is determined that only 76 is connected, the setting of the fixing device 33 that has reached the end of its life or requires replacement is determined.

Next, the initial operation when the power is turned on in the above configuration will be explained with reference to the flowchart shown in FIG. 17. For example, now the power switch 68 is turned on. Then, the control circuit 133 reads the setting state of the input terminal changeover switch 70. As a result, the setting status of the input terminal selector switch 70 is changed to 100V, 120V,
V.

The voltage specification of 220V is read. Next, the control circuit 133 reads the status of the fuses 174, . . . in the fixing device 33. That is, transistor Ta is turned off, transistors Tb and Tc are turned on,
The states of the fuses 174, . . . are read through the buffers 192, 193, 194. As a result, the control circuit 133 compares the operating voltage of the image forming apparatus and the voltage specification of the fixing device 33, and if there is a mismatch, displays this using the display circuit 134, and the driver 152
By turning off 5SR 165, no AC input voltage is supplied to heater lamp 40. This can prevent fixing failure or thermal melting of the fixing device 33 caused by a difference between the operating voltage of the image forming apparatus and the voltage specifications of the fixing device 33.

Further, when the operating voltage of the image forming apparatus and the voltage specification of the fixing device 33 match, the control circuit 133 determines whether the fuse is new or old based on the connection state of the fuses 174, . . . . If the product is new, the control circuit 133 clears the counter for life management of the fixing device in the memory 153, and clears the transistors Ta and Tb in the fuse determination circuit 173.
Turn on.

From this point, a power supply voltage of +24V is applied to the fuse 176, and it is blown (cut). Next, the control circuit 133 uses the display circuit 134 to display the life span of the fixing device 33 when the fuse 176 is disconnected, and when the fuse 176 is not disconnected,
The count value of a counter for managing the lifespan of the fixing device 33 in the memory 153 is read out, and it is determined whether the lifespan of the fixing device 33 has exceeded 80,000 sheets. If the lifespan has been exceeded, transistors Ta and Tc are turned on. As a result, the power supply voltage +24V is applied to the fuse 174 or 175,
It is fused (cut). Next, the control circuit 133
uses the display circuit 134 to display that the fixing device 33 has reached the end of its life. If the lifespan has not been exceeded, the control circuit 133 ends the initial operation.

In this way, the operating voltage of the image forming apparatus and the voltage specifications of the fixing device 33 can be compared using the fuses 174 and 175 for life management.
Even if the fixing device 33 with a different voltage specification is mistakenly switched on, the power will not be turned on, and defective fixing or thermal melting of the fixing device 33 can be prevented.

In addition, by providing a fuse for distinguishing new from old and a fuse for discriminating lifespan inside the fixing device 33, the fixing device 33
3 lifespan can be easily and reliably managed. The management method using these two fuses can be applied not only to the fixing device but also to other drum devices and developing devices that require life management and destination management.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that can prevent failures even if an error occurs in the setting of the operating range for the AC input voltage.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram schematically showing the overall configuration, FIG. 2 is an external perspective view of the image forming apparatus, and FIG. 3 is a vertical cross-sectional side view of the image forming apparatus. figure,
Fig. 4 is a partial vertical side view of the image forming apparatus, Fig. 5 is an external perspective view of the image forming apparatus with the top cover open, and Fig. 6 explains the connection relationship between the apparatus main body and the AC power cord. Figure 7 is a perspective view showing the configuration of the AC power cord, Figure 8 is a plan view showing the configuration behind the main body of the device, and Figure 9 is the state of supply of AC input voltage to the heater lamp. 10 is an electric circuit diagram showing the configuration of the overvoltage protection device, and FIG. 11 shows the lighting state of the display corresponding to the setting position of the input terminal selector switch, the operating voltage range,
A diagram for explaining the state of the bidirectional thyristor, FIG. 12 is a diagram showing the signal waveform of the main part in the i4@pressure protection circuit,
13 and 14 are plan views for explaining the connection section provided at the bottom of the fixing device, FIG. 15 is a diagram showing the configuration of fuses and a fuse determination circuit in the fixing device, and FIG. 16 is a diagram showing the structure of the fuse in the fixing device. FIG. 17, which is a diagram for explaining the voltage specification determination method of the device, is a flowchart for explaining the initial operation when the power is turned on. 33... Fixing device, 68... Main switch, 70
...Input voltage selection switch, 71...Blue indicator,
72... Red indicator, 133... Control circuit, 134... Display circuit, 152... Driver, 15B... Memory, 161... Overvoltage protection device, 162... Overvoltage protection circuit, 163...Internal circuit, 172...Connection section, 173...Fuse determination circuit, 174-176...Fuse.

Claims (4)

[Claims] (1) An image forming apparatus configured to have fixing devices having different operating voltage ranges that are detachably attached and forming an image, an output means for outputting a power supply voltage, an instruction means for indicating an operating voltage range of the fixing device; An image forming apparatus comprising: determination means for determining whether the output voltage from the output means is within the operating voltage range instructed by the instruction means. (2) An image forming apparatus configured to have fixing devices having different operating voltage ranges that are detachable and forming an image, an output means for outputting a power supply voltage, and an instruction means for indicating an operating voltage range of the fixing device; determining means for determining whether the output voltage from the output means is within the operating voltage range instructed by the indicating means; and as a result of the determination by the determining means, if the output voltage is within the operating voltage range; and supply means for supplying the output voltage from the output means to the fixing device. (3) An image forming apparatus configured to have fixing devices having different operating voltage ranges that are detachable and forming an image, an output means for outputting a power supply voltage, an instruction means for indicating an operating voltage range of the fixing device; determining means for determining whether the output voltage from the output means is within the operating voltage range instructed by the indicating means; and as a result of the determination by the determining means, if the output voltage is within the operating voltage range; , supply means for supplying the output voltage from the output means to the fixing device, and when the output voltage is outside the operating voltage range as a result of determination by the determination means, the output voltage is outside the operating voltage range. An image forming apparatus comprising: a display means for displaying. (4) An image forming apparatus configured to have fixing devices having different operating voltage ranges that are detachably attached and forming an image, an output means for outputting a power supply voltage, and an instruction means for indicating an operating voltage range of the fixing device; determining means for determining whether the output voltage from the output means is within the operating voltage range instructed by the indicating means; and as a result of the determination by the determining means, if the output voltage is within the operating voltage range; , a supply means for supplying the output voltage from the output means to the fixing device; and a supply means for supplying the output voltage from the output means to the fixing device; and if the output voltage is smaller than the operating voltage range as a result of determination by the determination means, displaying a message to that effect; 1. An image forming apparatus comprising: display means for displaying a message to that effect when the voltage is larger than an operating voltage range.